Figure 2 - full size

 

Figure 2.
Stereo pair showing that the backbone structures of L20/R63A lysozyme complexed with guanidinium ion (red), methylguanidinium (yellow), and ethylguanidinium (green) are virtually identical. The structure of L20/R63A in the absence of ligand (cyan) differs substantially.

The above figure is reprinted from an Open Access publication published by the Protein Society: Protein Sci (2006, 15, 853-861) copyright 2006.